From the Magazine

Dinosaur metabolism neither hot nor cold, but just right

Paleontologists have struggled for 50 years to determine whether dinosaurs were cold-blooded like today's reptiles or warm-blooded like most modern mammals and birds. A study on page 1268 examines the growth and metabolic rates of nearly 400 living and extinct animals, and concludes that neither was right. Instead, dinosaurs had an in-between metabolism.